<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script type="text/javascript">
        var num = 4;
        switch (num) {
            case 1:
                console.log("星期一");
                break;
            case 2:
                console.log("星期二");
                break;
            case 3:
                console.log("星期三");
                break;
            case 4:
                console.log("星期四");
                break;
            case 5:
                console.log("星期五");
                break;
            case 6:
                console.log("星期六");
                break;
            case 7:
                console.log("星期日");
                break;
            default:
                console.log("你输入的数据有误");
                break;
        }
    </script>
</body>

</html>